import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class Anime {
public static void main(String[] args) {
String url = "jdbc:mysql://xx.xxx.xxx.xx:3306/wordpress";
String user_name = "root";
String pass = "mypassword_is_here";
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection conn = DriverManager.getConnection(url,user_name, pass);
} catch ( Exception e ) {
e.printStackTrace();
}
}
}
And I keep getting this error
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at Anime.main(Anime.java:17)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 15 more
Now I've looked around stackoverflow and it seems like this is usually because the url isn't correct or sometimes there is a firewall issue or the wait_timeout variable in mysql is too low (it isn't in my case).
By the way, I am trying to connect to an external database on a centOS linux server running mySQL.
So I'm wondering how I can test the URL outside the program to really see if it's because of the URL or the firewall or any of that for the matter. If you guys got any solutions, please let me know.
Related
This question already has answers here:
Connect Java to a MySQL database
(14 answers)
Closed 7 years ago.
I have created a MySQL database at hostinger.co.uk and now I am trying to make connection between the database and my Java application, and for that I have written this Java code:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class DB_Connection {
public static void main(String arg[]) throws Exception {
makeConnection("u335300563_myName", "pass12345");
}
public static void makeConnection(String username, String password) throws Exception {
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://u335300563_database",username,password);
PreparedStatement statement = connection.prepareStatement("select * from example");
ResultSet result = statement.executeQuery();
for(int i=1; result.next(); i++)
System.out.println(result.getString(i));
}
}
But this is throwing an exception that is:
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1036)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:338)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2232)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2265)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2064)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:395)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at DB_Connection.makeConnection(DB_Connection.java:14)
at DB_Connection.main(DB_Connection.java:9)
Caused by: java.net.UnknownHostException: u335300563_database
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(Unknown Source)
at java.net.InetAddress.getAddressesFromNameService(Unknown Source)
at java.net.InetAddress.getAllByName0(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:190)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:297)
... 16 more
So please tell what is the problem?
Caused by: java.net.UnknownHostException: u335300563_database
Program failed to identify the host of mysql DB.
In program, you have to pass correct hostname or IP address of the system hosted your mySQL:
Following line need to correct from
DriverManager.getConnection("jdbc:mysql://u335300563_database"
,username,password);
To
DriverManager.getConnection("jdbc:mysql://<IP Address of MySQL DB server or correct hostname with port number >",
username,password);
I try to install openfire but I have some error, I don't understand why I cannot install successfully Openfire 3.9.3 . when I choose : Standard Database Connection
Use an external database with the built-in connection pool.
=> I use http://localhost/phpmyadmin/ for mysql
Database Driver Presets:MySql
JDBC Driver Class:com.mysql.jdbc.Driver
Database URL:jdbc:mysql://[localhost]:3306/[dbopenfire]?rewriteBatchedStatements=true
Username:root
//Left blank
Password:
what is the problem?
many thanks.
error.log:
2014.07.27 20:57:33 org.jivesoftware.util.log.util.CommonsLogFactory - Prototype
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor13.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1127)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:356)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2502)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2539)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2321)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.GeneratedConstructorAccessor10.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)
Caused by: java.net.UnknownHostException: [localhost]
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:250)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:306)
... 17 more
2014.07.27 20:58:03 org.jivesoftware.util.log.util.CommonsLogFactory - Prototype
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.GeneratedConstructorAccessor13.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1127)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:356)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2502)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2539)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2321)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.GeneratedConstructorAccessor10.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:409)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
at org.logicalcobwebs.proxool.Prototyper.sweep(Prototyper.java:102)
at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:44)
Caused by: java.net.UnknownHostException: [localhost]
at java.net.InetAddress.getAllByName(Unknown Source)
at java.net.InetAddress.getAllByName(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:250)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:306)
... 17 more
It seems lately, my JavaFX app always tries to connect to something upon launch.
This process hangs my app for a bit and makes my app startup time about 20 seconds more longer. This is the error I see:
java.net.ConnectException: Connection timed out: connect
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Sou
rce)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unkno
wn Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown So
urce)
at com.sun.deploy.net.proxy.AbstractAutoProxyHandler.getJSFileFromURL(Un
known Source)
at com.sun.deploy.net.proxy.AbstractAutoProxyHandler.init(Unknown Source
)
at com.sun.deploy.net.proxy.DynamicProxyManager.reset(Unknown Source)
at com.sun.deploy.net.proxy.DeployProxySelector.reset(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.javafx.main.Main.tryToSetProxy(Main.java:572)
at com.javafx.main.Main.launchApp(Main.java:640)
at com.javafx.main.Main.main(Main.java:805)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.<init>(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.http.HttpClient.New(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown
Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Sour
ce)
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown So
urce)
at sun.net.www.protocol.http.HttpURLConnection.getHeaderField(Unknown So
urce)
at java.net.URLConnection.getContentType(Unknown Source)
at com.sun.deploy.net.proxy.AbstractAutoProxyHandler.isSupportedINSFile(
Unknown Source)
... 10 more
I don't see it trying to connect if I'm running from the IDE. So is this some sort of oracle-based spying attempt? What gives?
I think it's trying to auto-detect a proxy somehow.
I was able to make this go away in the Java Control Panel. On the General tab, in the Network Settings... dialog, switch from Use browser settings to Direct connection.
(I couldn't find any proxy settings specified in either Firefox or IE, though.)
I followed this step for configuration http://jmeter.apache.org/usermanual/remote-test.html
The 2 machines are on same subnet.
They can ping each other
Windows firewall is turned off
When I execute remote start its give a "Connection refused" exception.
error log
2011/12/07 13:39:37 ERROR - jmeter.gui.action.RemoteStart: Failed to initialise remote engine java.rmi.ConnectException: Connection refused to host: 198.168.137.4; nested exception is:
java.net.ConnectException: Connection timed out: connect
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
at sun.rmi.server.UnicastRef.newCall(Unknown Source)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Unknown Source)
at org.apache.jmeter.engine.ClientJMeterEngine.getEngine(ClientJMeterEngine.java:56)
at org.apache.jmeter.engine.ClientJMeterEngine.<init>(ClientJMeterEngine.java:69)
at org.apache.jmeter.gui.action.RemoteStart.doRemoteInit(RemoteStart.java:176)
at org.apache.jmeter.gui.action.RemoteStart.doAction(RemoteStart.java:79)
at org.apache.jmeter.gui.action.ActionRouter.performAction(ActionRouter.java:82)
at org.apache.jmeter.gui.action.ActionRouter.access$000(ActionRouter.java:42)
at org.apache.jmeter.gui.action.ActionRouter$1.run(ActionRouter.java:61)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
... 27 more
Check whether your RMI port on your other machine(s) is closed? jMeter uses 1099 by default.
Use cmd and type:
telnet [ip-address] 1099
You, of course, started the jMeter server on all machines, right?
this problem is resolve
my computer is connected to the internet and when i start jmeter-server its start on public ip.
my ip is 192.168.137.1 but some how its start on my public ip when i check on google with my public ip is same
i stop internet and start jmeter-serrver again its working
thanks
Most recent problem is "Third Error" listed below.
I am working on an application in java that needs to connect to a database. Below is the code that i am using to attempt to connect to the database. The port is 3306 and i have the database set up on a machine here at my house on the network. For the ip address i am just using my external ip address to the world. The username and password were replaced for my protection. In my /etc/mysql/my.cnf, "bind_address" is commented out.
I have tried several things and can not seem to get this to work. This is my first time using JDBC... thanks for any help! Let me know if you need more information.
Class.forName("com.mysql.jdbc.Driver").newInstance();
System.out.println("before connection");
connect = DriverManager.getConnection("jdbc:mysql://ip-address/mjla_db", "username", "password");
System.out.println("connection established");
Here is the error that i keep getting:
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at school.cs321.mjla.MJLA.main(MJLA.java:30)
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 15 more
Second Error
After changing ip address to the internal ip address of the server.
java.sql.SQLException: null, message from server: "Host '192.168.1.102' is not allowed to connect to this MySQL server"
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1128)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2336)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at school.cs321.mjla.MJLA.main(MJLA.java:30)
Third error
When trying to access the database with the external ip address on an external network, i get the same error that i had initially.
I am using the "%" wild card for the Host of the username i am using for the application to authenticate to the database.
#Dave Newton: I was making the assumption that my firewall still had the port open for mysql, because i just got through working on a project where i did the same thing. However, i must have closed it a couple months ago. I checked a few minutes ago and it was disabled. So, i enabled and it is working fine now. Not sure why it had been closed...
Are you sure that the IP address in getConnection is correct? Can you try with
telnet youserver 3306
to see if there is a connection problem? Is there a firewall on the server?
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/student", "root", "root");
just try it